acg_gis.py

import sys
import requests

URL_BASE = "https://gis.arlingtonva.us:6443/arcgis/rest/services/"
TIMEOUT = 5


def find_address_candidate(single_line):
    path = "geoproc/Composite_Add_loc/GeocodeServer/findAddressCandidates"
    params = {
        "SingleLine": single_line,
        "maxLocations": "1",
        "outSR": "4326",
        "f": "pjson",
    }
    try:
        r = requests.get(URL_BASE + path, params=params, timeout=TIMEOUT)
        candidate = r.json()["candidates"][0]
        return (
            candidate["address"],
            candidate["location"]["x"],
            candidate["location"]["y"],
        )
    except (requests.exceptions.RequestException, IndexError, TypeError):
        return None


def identify(service, x, y, layers=None):
    path = "public/{}/MapServer/identify".format(service)
    params = {
        "geometry": "{},{}".format(x, y),
        "geometryType": "esriGeometryPoint",
        "sr": "4326",
        "tolerance": "10",
        "mapExtent": "10",
        "imageDisplay": "600,550,96",
        "returnGeometry": "false",
        "returnZ": "false",
        "returnM": "false",
        "f": "pjson",
    }
    if layers:
        params["layers"] = layers
    r = requests.get(URL_BASE + path, params=params, timeout=TIMEOUT)
    return r.json()


def civic_association(x, y):
    try:
        return identify("Civic_Associations", x, y)["results"][0]["value"]
    except (IndexError, TypeError):
        return "Unknown"


def police_district(x, y):
    try:
        return identify("Police_Districts", x, y)["results"][0]["value"]
    except (IndexError, TypeError):
        return "Unknown"


def polling_place(x, y):
    try:
        precinct = identify("Voter_Locations", x, y, layers="4")["results"][0]["attributes"]
        return "{}, {}".format(precinct["POLLING_PLACE"], precinct["ADDRESS"])
    except (IndexError, TypeError):
        return "Unknown"


def high_school(x, y):
    try:
        school = identify("High_school_boundary", x, y)["results"][0]["attributes"]
        return "{}, {}".format(school["SCHOOL_NAM"], school["ADDRESS"])
    except (IndexError, TypeError):
        return "Unknown"


def middle_school(x, y):
    try:
        school = identify("Middle_school_boundary", x, y)["results"][0]["attributes"]
        return "{}, {}".format(school["SCHOOL_NAM"], school["ADDRESS"])
    except (IndexError, TypeError):
        return "Unknown"


def elementary_school(x, y):
    try:
        school = identify("Elementary_school_boundary", x, y, layers="3")["results"][0]["attributes"]
        return "{}, {}".format(school["SCHOOL_NAM"], school["ADDRESS"])
    except (IndexError, TypeError):
        return "Unknown"


if __name__ == "__main__":
    candidate = find_address_candidate(sys.argv[1])
    if candidate:
        lon = candidate[1]
        lat = candidate[2]
        print "Address standardized as:", candidate[0]
        print "Latitude:", lat
        print "Longitude:", lon
        print "Civic Association:", civic_association(lon, lat)
        print "Polling Place:", polling_place(lon, lat)
        print "Police District:", police_district(lon, lat)
        print "Elementary School:", elementary_school(lon, lat)
        print "Middle School:", middle_school(lon, lat)
        print "High School:", high_school(lon, lat)

gis_trails.py

import requests
import geojson
from collections import defaultdict

TRAILS_URL = "http://gisdata.arlgis.opendata.arcgis.com/datasets/add6458ac5b241368d459fce8e53cfe9_1.geojson"

r = requests.get(TRAILS_URL)
trails = geojson.loads(r.text)
length_ft = sum([i["properties"]["SHAPElen"] for i in trails["features"]])
print "Total miles:", length_ft / 5280

lengths = defaultdict(int)
for i in trails["features"]:
    lengths[i["properties"]["TRAIL_NAME"]] += i["properties"]["SHAPElen"]

for i in sorted(lengths.keys()):
    print "{0},{1:04.2f}".format(i, lengths[i]/5280)

results.txt

2016-07-29

https://gis.arlingtonva.us:6443/arcgis/rest/services/geoproc/Composite_Add_loc/GeocodeServer/findAddressCandidates?SingleLine=2100+clarendon+blvd&maxLocations=1&f=pjson&callback=foo
foo({
 "spatialReference": {
  "wkid": 102746,
  "latestWkid": 2283
 },
 "candidates": [
  {
   "address": "2100 CLARENDON BLVD",
   "location": {
    "x": 11885559.359552318,
    "y": 7010448.2899357406
   },
   "score": 100,
   "attributes": {
    
   }
  }
 ]
});

http://gis.arlingtonva.us/arlgis/rest/services/public/Fireboxes/MapServer/identify?geometry=-77.085343040321547%2C38.890487388176247&geometryType=esriGeometryPoint&sr=4326&layers=&layerDefs=&time=&layerTimeOptions=&tolerance=10&mapExtent=10&imageDisplay=600%2C550%2C96&returnGeometry=false&maxAllowableOffset=&geometryPrecision=&dynamicLayers=&returnZ=false&returnM=false&gdbVersion=&f=pjson
{
 "results": [
  {
   "layerId": 1,
   "layerName": "Fireboxes",
   "displayFieldName": "FIRSTDUE",
   "value": "Station 10",
   "attributes": {
    "OBJECTID": "118",
    "BOX_NUM": "11003",
    "FIRSTDUE": "Station 10",
    "HWY": "0",
    "FIRE_STATION": "0",
    "BOX_TEXT": "110-03",
    "COLOR": "1",
    "Shape": "Polygon",
    "SHAPE.STArea()": "7364570.060817",
    "SHAPE.STLength()": "11661.22042"
   }
  }
 ]
}